Closet door having high-low return air supply for air conditioner

ABSTRACT

An air conditioner housed within the closet of a living space, particularly an apartment, said closet having a special door construction equipped with dampered openings adjacent its top and bottom edges. During the cooling season the air conditioner draws its supply air from the upper door openings and during the heating season the air conditioner draws its supply air through the lower door openings. The invention improves the air conditioner efficiency and minimizes stratification and temperature differentials between the floor and ceiling.

United States Patent Inventor Joseph D. Loveley Grosse Pointe Woods,Mich. App]. No. 33,2l Filed Apr. 30, 1970 Patented Oct. 19, 197 lAssignee American Standard Inc.

New York, N.Y.

CLOSET DOOR HAI/ING HIGH-LOW RETURN AIR SUPPLY FOR AIR CONDITIONER 4Claims, 6 Drawing Figs. U.S. Cl 165/48, 98/33 A Int. Cl F 25b 29/00Field of Search 165/48, 57; 98/33 R, 33 A -[56] References Cited UNITEDSTATES PATENTS 2,021,583 11/1935 Whiteley 98/33 A 2,259,780 10/1941 Seid98/33 R Primary Examiner-Carrol] B. Dority, Jr. An0rneysJohn E. McRae,Tennes I. Erstad and Robert G.

Crooks ABSTRACT: An air conditioner housed within the closet of a livingspace, particularly an apartment, said closet having a special doorconstruction equipped with dampered openings CLOSET DOOR HAVINGIIIGI-ll-LOW RETURN AIR SUPPLY FOR AIR CONDITIONER THE DRAWINGS FIG. 1schematically illustrates a closet-air-conditioner arrangementincorporating the invention.

FIG. 2 is an enlarged sectional view through a portion of the closetdoor in FIG. I.

FIG. 3 is a fragmentary view similar to FIG. 2, but showing certaindampers in adjusted positions.

FIG. 4 is a fragmentary sectional view on line 4-4 in FIG. 3.

FIG. 5 is a view through a louver that may be used in practice of theinvention.

FIG. 6 is a fragmentary sectional view through another door constructionutilizing the invention.

FIG. I IN GREATER DETAIL FIG. I shows a closet l0 defined by an outsidebuilding wall 12, a floor 14 and a ceiling 16. The front wall 18 of thecloset is provided with a door opening 20 arranged to be closed by aswinging or sliding door 22 of sufficient adult height to permit walkin. Nonnally the closet would be located in one of the rooms or at theend of a hallway. Arranged within the closet is an air conditioner 26 ofrectangular shape. As shown, the conditioner housing is subdivided by avertical partition 28 into an outer compartment 30 and an innercompartment 31. Arranged within the outer compartment is a refrigerantcompressor 34, refrigerant condenser coil 36, and motor-driven fan 38.As shown in FIG. I, the fan draws outside air into compartment 38through an intake opening 40; the air is forced upwardly throughcondenser coil 36 and out through an opening 42, thereby causing therefrigerant flowing through the condenser coil to be condensed in theusual manner.

Compartment 31 contains a centrifugal blower 44 which receives its airsupply from a louvered inlet opening 46, and which discharges its airupwardly through a refrigerant evaporator coil 48 heating unit 50(electrical resistance heater, gas-fired heat exchange unit, etc.

During the heating season the compressor 34 is inactive so that coil 48does not cool the air flowing upwardly from blower 44; at this time theheating unit 50 may be periodically energized by a room thermostat, (notshown), so that the upflowing air is heated and delivered to a verticalriser duct 52. The heated air is distributed to the rooms via one ormore horizontal branch ducts 54.

During the cooling season the heating unit 50 is deenergized, and therefrigerant compressor 34 is energized so that upflowing air from blower44 is cooled as it passes through coil 48; the cooled air is distributedto the rooms through ducts 52 and 54.

SUPPLY AIR FOR THE CONDITIONER In multifloor home air-conditioningsystems it is common to provide return air registers in each room. Suchreturn registers connect with a common return duct which returns the airto the central air conditioner for heating during winter and coolingduring summer. In single floor residences, particularly apartments, thereturn air may be supplied merely through open doorways.

In the present invention, (designed particularly for single floorresidences) the return air for the conditioner is taken from space 60 infront of the closet door 22; this may be either a hallway or a room. Asshown by the flow arrows in FIG. ll, the air can move through an upperpassage 56 in the door (cooling season) or through a lower passage 58(heating season). As will be apparent hereinafter, dampers in the twopassages preclude simultaneous air flow through both passages; when oneis closed the other is open, and vice versa.

AIR STRATIFICATION During the heating season it is desirable that returnair be taken from points in room 60 near the floor because the floor airis cooler and has an uncomfortable feeling. During the cooling season itis desirable that the return air be taken from points in room 60 nearthe ceiling because the ceiling air will be hotter and the leastcomfortable. In conventional arrangements the return air is usuallytaken from the same point during both seasons, either near the ceilingor near the floor, depending on the particular compromise chosen. Withconventional arrangements the occupants are not completely comfortableon a year round basis, since as much as a 10 tempera ture differentialoften exists between floor level and areas about 6 feet above the floor(in moderate weather 55 F. there is little differential). It is anobject of the present invention to provide an arrangement thateliminates or minimizes this air stratification or temperaturedifferential feature.

HEATING COOLING PERFORMANCE In general the performance of the airconditioner is improved by increasing the temperature differentialbetween the entering air stream (through louver 46) and the dischargestream (through duct 52). Thus, during the cooling season therefrigerant evaporator will produce more air cooling when the enteringtemperature at louvers 46 is relatively high; during the heating seasonthe air conditioner will provide more heating when the entering airtemperature through louvers 46 is relatively low.

In the air cooling mode a high entering air temperature means a greatertemperature differential between the air and refrigerant, thus tendingto increase the average mass flow of refrigerant to satisfy the demand.The cooling unit therefore tends to operate nearer its rated capacity. Acooling unit fully rated at F. entering air temperature might have onlyabout 82 percent of rated capacity with entering temperatures of about70 F.

In the air-heating mode a low entering air temperature means a greatertemperature differential between the air and heater surface (electric orflame-heated). The larger temperature differential means greater heattransfer and operation closer to rated heater capacity.

The illustrated arrangement of dampered passages 56 and 58 provides thedesired entering air temperatures, and thus improves the capacity of theair conditioner to heat in the winter and cool in the summer. It maythus be possible by using the described dampered passages to reduce thesize of air conditioner needed for a given room area and geographicallocation.

LOCATION OF AIR RETURNS As shown in FIG. I the closet door 22 isprovided with an air passage 56 adjacent its upper edge i.e. about 7feet from the floor, and a second air passage 58 adjacent its loweredge, i.ev about one -half foot off the floor. Each air passage 56 or 58is provided with an individual damper so that the upper passage can beclosed while the lower passage is open, and vice versa. During thecooling season it is contemplated that passage 58 will be closed andpassage 56 opened. Blower 44 will draw air from room 60 through theupper passage 56, thereby tending to minimize the aforementionedstratification problem. During the heating season it is contemplatedthat passage 56 will be closed and passage 58 opened so that blower 44will draw air from the room 60 at points adjacent floor I4, thus tendingto minimize the stratification problem during the heating season.

DOOR-PASSAGE CONSTRUCTION As shown in FIG. 2, a typical closet door 22is formed by a honeycomb core 62 and facing panels 64 and 66. Thehoneycomb may be formed for example of resin-impregnated Kraft paperarranged with the honeycomb passages horizontal and normal to the doorplane. The front and rear edges of the honeycomb may be adhered to themetal or plywood panels 64 and 66. The invention is not dependent on theuse of panelsurfaced honeycomb construction; however this structure doeshave some sound absorption characteristics, and is thus well adapted forthe purpose. Conventional panel wooden door construction is believedalso suitable.

FIG. 2 illustrates a section of the door having an opening therethroughwhich defines the aforementioned passageway 58. As shown, the passagewaycomprises a metal frame 77 having a lower frame wall 68 and an upperframe wall 70. Additional unnumbered sidewalls complete the frame.Extending horizontally between the frame sidewalls are three pivotshafts 72, each shaft being secured to and supporting a butterfly dampervane element 74. FIG. 2 illustrates the damper vanes in the closedposition while FIG. 3 illustrates one of the dampers in an openedposition.

Each shaft 72 has a platelike arm or link 76 welded thereto at or nearthe shaft midpoint. The various arms 76 are linked together by means ofa vertical tiebar 78. As best shown in FIG. 4, a suitable pin 80 goesthrough each arm 76 and the tiebar to form a pivotal connection, wherebyvertical movement of the tiebar is effective to rotate the individualdampers 74 between their FIG. 2 and FIG. 3 positions.

To effect vertical movement of tiebar 78 there is provided a verticalrod 82 suitably mounted in a slideway 84 affixed to the rear panel 66 ofthe door; a similar slideway (not shown) shown) would guide the upperportion of rod 82. Rod 82 includes a block element 88 which has a slot90 extending laterally therethrough for accommodating a roller 92carried on one of the pins 80. It will be seen that downward movement ofrod 82 will cause block 88 to force the tiebar 78 downwardly with arolling engagement between roller 92 and the upper surface of slot 90;this action causes the three damper vanes 74 to move from their FIG. 2closed positions to their FIG. 3 opened positions. In the openedposition the dampers permit room air to flow through the door passageinto the closet I for eventual flow through the air conditioner, aspreviously explained.

DAMPER OPERATION It is contemplated that passage 56 in the upper portionof the closet door would have damper vanes similar to the three vanes 74shown in passage 58. These upper vanes would be operated by the same rod82 that is used to operate the passage 58 damper vanes. However since itis desired that passage 56 be closed when passage 58 is open, and viceversa, the upper damper vanes must have a different relation to theupper block 88. This may be accomplished by disposing the upper damperassembly in an upside down relation; i.e. frame wall 68 would be the topwall of the frame, and frame wall 70 would be the bottom wall of theframe. The upper block element 88 would be located at the correct pointon rod 82, as by a set screw adjustment.

Rod 82 could be actuated from either side of the door, i.e. front orrear. As shown in FIG. I, the actuating connection is locatedfront-side, in the form of a handle 96 on the door front face. Asuitable bar 94a may extend from red 82 forwardly through a slot in thedoor to connection with the actuating knob 96 on the front face of thedoor. Movement of the knob upwardly would close the lower set of dampersin passage 58 For thereby adapting the mechanism to cooling operation.Movement of Knob 96 downward wound close the dampers in passage 56 thusadapting the mechanism to heating operation. Suitable indicia on thefront face of the door would indicate to the user the correct knobposition for each season. Preferably a latch would be built into knob 96to hold the dampers in their adjusted positions in spite of gravity andair pressure forces on the damper vanes.

PASSAGE DIMENSION A typical apartment size air conditioner might requirean air flow of about 1,200 cubic feet per minute through blower 44 andthe air-conditioning components. Passages 56 and 58 must be ofsufficient size to handle this air flow without introducing appreciablepressure drop or excessive sound pulsation Generally the linear air flowrate through each passage (56 or 58) should be no higher than about 800feet per minute. With a door width of about 26 inches each rectangularframe 77 could be sized to define an air opening on the order of 20inches wide by 9 inches high. Assuming each vane 74 to be about 2 incheswide (about the depth of the door), four or five vanes would be requiredin each passage. Merely for illustration purposes FIG. 2 shows threevanes; in practice a greater number of dampers might be necessary.Different size air conditioners require different passage dimensions sothat linear flow in all cases is kept below about 800 feet per minute.

SOUND ABSORPTION During operation of the air conditioner air flowthrough blower 44 and through fan 38 may produce some objectionablenoise; compressor 34 and duct 52 may also produce some noise. It isdesirable that such noises be minimized as much as possible because theair conditioner would usually be located closely adjacent the livingareas, and not in the basement. Much of the noise can be dampened bylining chambers 30 and 31 with sound-absorbent material, and by encasingduct 52 in a sound-absorbent sleeve. However inevitably some blower 44noise propagates back through louvers 46 toward room 60. To minimizesuch noise propagation into the room the door 22 preferably has securedto its rear face a sound-absorbent panel 94; the panel may beperipherally flanged, as at 96, and secured to door panel 66 by screws,welding, etc. Panel 94 is perforated as at 98, and lined with suitablesound insulation 101, such as urethane foam, felt, may-type fiberglass,celotex, mineral fiber, etc. Also, the areas of plate 94 in directregistry with passage 58 may be louvered, as at 100, so that passage 58has no direct line of sight with the louvers 46 on the air conditioner.The louvers thus prevent sound waves eminating through louvers 46 fromblasting through passage 58 when the dampers 74 are in the openposition. Additional sound insulation may be provided around theperiphery of the passage 58, as at 103. Various other soundabsorbingtechniques can be used. For example, dampers 74 can be constructed toinclude sound-absorbent material as shown in FIG. 5. As there shown,each damper 74a is formed by two spaced sheets 75 and 77, and theinterior space filled with sound-absorbent material 79.

WHY PLACE THE AIR RETURNS IN THE DOOR? As shown in FIG. 1, the airconditioner is disposed in a closet having a fixed front wall 18.Although not shown, the closet preferably has a width that is onlyslightly greater than the width of the air conditioner, the aim being toreduce the closet dimension and thereby increase the useful living area.When the air conditioner is employed in a closet of very small width thedoor 22 occupies substantially the entire width of the closet; the dooritself is therefore the only structure available for reception of thereturn air inlets 56 and 58.

It should also be noted that doors are commonly manufactured infactories, and that the louvered damper construction as shown in FIGS. 2and 3 is most conventionally manufactured and installed by factorymethods. Therefore manufacturing economies tend to dictate that thehigh-low returns be incorporated in the door rather than in fixed wallstructures. Preferably however the air passages are incorporated withthe least possible modification of the conventional door structure. Asshown in FIG. 2, the door is conventional except that a rectangular holehas been cut to accommodate frame 77. Rod 82 is installed on the doorafter the frame 77 has been mounted in the door opening. Preferably theactuating device 82 is located outside the door (i.e. outside the spacebetween panels 64 and 66) to avoid special door-manufacturing techniquesor skills.

FIG. 6

FIG. 6 shown in horizontal section a door similar to the door of FIG. 2,except that front door panel 64 is perforated to provide verticalshotlike passageways 65. A perforated damper plate 67 is slidablypositioned on the front face of panel 64 for lateral slidable movementwithin frame 69 in the arrow 7] directions; frame 69 is held on panel 64by screws, welding, etc. It will be seen that manual adjustment ofdamper 67 via knob 73 can be employed to open and close the air passages65.

In practice the FIG. 6 damper assembly would be duplicated near the topand bottom edges of the door to provide the highlow air return featureof FIG 1.

I claim:

1. Building construction comprising a closet communicating with a roomthrough a door opening of adult height; an air conditioner locatedwithin the closet; said conditioner comprising (l) a casing having areturn air inlet for receiving air from the closet space, (2) anair-heating unit within the casing, (3) an air-cooling unit within thecasing, and (4) an air blower for flowing air from the casing inletthrough the heating and cooling units to the casing outlet: theimprovement comprising a door for the closet opening; said door having afirst air passage therethrough adjacent its upper edge and a second airpassage therethrough adjacent its lower edge, an upper damper operableto close the upper air passage during the heating season, and a lowerdamper operable to close the lower air passage during the coolingseason; whereby the air conditioner receives air solely from the lowerspaces of the room during the heating season, and whereby the airconditioner receives air solely from the upper spaces of the room duringthe cooling season.

2. The construction of claim 1 and further including a mechanicalconnection between the dampers whereby move ment of one damper to theclosed position automatically moves the other damper to the openposition, and vice versa.

3. The construction of claim I wherein each damper comprises a set ofbutterfly vanes, the arrangement further including manually movable rodmeans interconnecting the two sets of damper vanes so that (l movementof the rod means in one direction causes the upper damper vanes to closeand the lower damper vanes to open, and (2) movement of the rod means inthe other direction causes the upper damper vanes to open and the lowerdamper vanes to close.

4. The construction of claim 3 wherein the damper vanes are arranged forparallel pivotal movements about horizontal axes.

1. Building construction comprising a closet communicating with a roomthrough a door opening of adult height; an air conditioner locatedwithin the closet; said conditioner comprising (1) a casing having areturn air inlet for receiving air from the closet space, (2) anair-heating unit within the casing, (3) an air-cooling unit within thecasing, and (4) an air blower for flowing air from the casing inletthrough the heating and cooling units to the casing outlet: theimprovement comprising a door for the closet opening; said door having afirst air passage therethrough adjacent its upper edge and a second airpassage therethrough adjacent its lower edge, an upper damper operableto close the upper air passage during the heating season, and a lowerdamper operable to close the lower air passage during the coolingseason; whereby the air conditioner receives air solely from the lowerspaces of the room during the heating season, and whereby the airconditioner receives air solely from the upper spaces of the room duringthe cooling season.
 2. The construction of claim 1 and further includinga mechanical connection between the dampers whereby movement of onedamper to the closed position automatically moves the other damper tothe open position, and vice versa.
 3. The construction of claim 1wherein each damper comprises a set of butterfly vanes, the arrangementfurther including manually movable rod means interconnecting the twosets of damper vanes so that (1 ) movement of the rod means in onedirection causes the upper damper vanes to close and the lower dampervanes to open, and (2) movement of the rod means in the other directioncauses the upper damper vanes to open and the lower damper vanes toclose.
 4. The construction of claim 3 wherein the damper vanes arearranged for parallel pivotal movements about horizontal axes.